Telemeter type hydraulic power transmitting system



NOV. 6, 195] J z s 2,573,943

TELEMETER TYPE HYDRAULIC POWER TRANSMITTING SYSTEM Filed April 10, 1948 5203222 07? F 72 waqvfi/ 2 2151614 Patented Nov. 6, 1951 TELEMETER TYPE HYDRAULIC POWER TRANSMITTING SYSTEM Joseph F. Ziskal, Cicero, 111., assignor to International Harvester Company, a corporation of New Jersey Application April 10, 1948, Serlal'No. 20,313

4 Claims. (Cl. 121-41) This invention concerns a hydraulic power transmitting system including a valve-closing servo-motor operable to close a control valve for terminating operation of such motor when a work member thereof has moved an amount correlated with the distance of valve-opening movement of a control member for such valve, and relates more particularly to such a system capable of employing a plurality of hydraulic rams interchangeably connectable in series with the motor and diiTering in bore and/or stroke but so related in fluid displacement capacity to that of the servo-motor that the position of the plunger of each ram throughout the range of its stroke is similarly correlated with the position of the valve control member within its adjusting range.

Heretofore, so far as I am aware, hydraulic power transmitting systems comprising a valveclosing servo-motor in series with an hydraulic ram have utilized a ram of the same fluid capacity and structural proportions as the motor when it was desired to cause the ram plunger to occupy positions in its range of movement respectively corresponding to positions of a control member for the valve closable by the motor. According to this invention it is possible for a system of such character to utilize an hydraulic ram of any desired bore and stroke and retain the operating feature that the ram piston will be caused to advance to positions located within.

its range of movement that correspond to positionsof the valve control member within its range of movement. This constitutes an important general object of the invention and is accomplished by making the displacement capacity of the piston-rod end of the ram equal to the displacement capacity of one end of a motor chamber which receives a vibratory work member of the motor, and communicatively connecting these two equal displacement spaces when connecting the motor and ram in series in the system. With such a design and arrangement of the ram with respect to the motor, the magnitude of the displacement capacity of the other two ends of the motor chamber and of the ram cylinder is immaterial.

Thus the invention further contemplates, and has as one of its objects, a plurality of rams of various bore and/or stroke but constructed with their piston rods of a diameter to make the displacement capacity of their cylinders at their piston-rod ends equal to the displacement capacity of the motor chamber with which such cylinder ends are to be communicatively connected, wherefore the rams are interchangeably disposable in the system where the position of their plunger can be correlated with the position of the valve control member. The improved ,system therefore embodies a basic counterpart including a valve control member and with which any of various rams may be combined to attain the desired length of operating stroke, speed of plunger movement, and magnitude of force exertable by the plunger. The system has particular utility when the basic part is installed upon and energized from a tractor, making it possible to, use and accurately control rams having proper operating characteristics for the manipulation of sundry equipment mounted upon or coupled tothe tractor.

A further object is the provision of an hydraulic power transmitting system employing a servo-motor energized by fluid flowing under control of a control valve when such valve is manipulated from a neutral setting, and the energized motor being operable to reset the control valve to neutral, together with check valves in respective fluid lines leading from the control valve to the motor, and valve means interposed between one of the check valves and the motor to selec-' mitting system constituting a preferred embodiment of this invention.

Fig. 2 is a sectional View taken axially through an hydraulic ram substitutable for the hydraulic ram shown in the lower part of Fig. 1 but having a different bore and stroke than the ram of Fig. 1.

Fig. 3 is a fragmentary view showing an alternative arrangement of a valve which controls communication of a part of the hydraulic circuit with fluid conducting power-take-off conduits.

Referring now particularly to Fig. 1, there will be seen a liquid source H having a high pressure outlet l2 and a low pressure inlet l3. There are also shown a control valve It, a manually operated control member [5 for the valve I 4, a servo-motor l6 operable through a link I! for resetting the valve M into a closed position for stopping operation of the motor I6 after the piston l8 therein has moved a distance correlated with the distance of movement of the manually s'ettable member IS in opening the valve for initiating energization of such motor. An hydraulic ram I9 is connected in series with the servomotor l6, wherefore the plunger 2| of this ram is caused to move concurrently with the movement of the piston l8. The servo-motor is operable through a piston rod 22 and an arm 22' for operating a rock-shaft 23 journaled in bearings 24, of which one is shown. An arm 25, which is constrained for oscillation with the rock-shaft 23, is adapted to transmit power to equipment (not shown) to be controlled by the apparatus.

While the control member and the piston I8 of the servo-motor l6 occupy correlated positions as illustrated in Fig. l, the. valve plunger 26 will be in a neutral position closing all ports in the valve casing 21. Consequently fluid drawn from the reservoir R through a conduit 28 by a constant delivery pump 29 will be discharged by that pump through a conduit 3| and thence through a conduit 32 into a chamber 33 of a valve 34. The pressure of this fluid is imposed through a conduit 35, but since enlarged portions 36 and 31 of the movable valve element 26 then block valve ports 38 and 39, fluid cannot escape from the conduit 35 and the full pressure of the fluid is imposed upon a valve piston 4| for unseating the valve ball 42. Fluid from the discharge side of the pump 29 can then by-pass past the valve 34 and through conduits 43 and 28 back to the reservoir or to the inlet side of the pump.

Manual movement of the control member l5 toward the limit A of its range of movement will manipulate the valve 26 for causing movement of the motor piston 16 toward the right or toward the piston rod end of the motor cylinder 45, whereas movement of the member l5 toward the limit C of its range of movement will adjust the control valve for causing .movement of the motor piston l8 toward the opposite end of the motor cylinder. Concurrently with movement of the control member l5, the movable valve element 26 is adjusted from its neutral position for causing termination of the low pressure by-pass condition of the fluid source H and creation of a high pressure condition. When, for instance the control member I5 is moved to the left toward position A, the enlargement 36 of the valve element 26 will be moved out of registry with ports 38 and 46, whereby fluid from the conduit 35 can escape through the ports 38 and 4-6 and the conduit l3 back to the reservoir R. Because of the restriction 41 in the conduit 32, the fluid can escape through the ports 38 and 46 sufflciently fast to diminish the pressure in the valve chamber 33 so that this pressure will be insufflcient to hold the by-pass valve ball 42 unseated. As a consequence this ball 42 will seat and close the by-pass valve and terminate low pressure bypass. The fluid at high pressure will then be delivered through the conduit l2 and control valve ports 48 and 49 into a reversible flow conduit 5| which leads through a check valve 52 to the left end of the motor cylinder 45. Fluid thus introduced into the left end of the motor cylinder will force the piston Hi to the right, displacing fluid from the piston rod end of said cylinder through a check valve 53 of which the ball 54 is then held open by the pressure of fluid above a piston 55. This fluid reaches the piston receiving chamber 56 through a conduit 51 from the conduit 5|. Because of the end area of the piston 55 exceeding the area of the seat for the ball 54, a pressure in the chamber 56 above the piston not necessarily exceeding the pressure in the spring chamber 58 will prevail over the pressure upon the ball 54 and cause this ball to be unseated. Fluid discharged from the piston rod end of the motor cylinder 45 past the check valve 53 and through a conduit 1| will be discharged into the piston rod end of the, ram cylinder 6| through a valve passage 62, a fluidconducting power take-off conduit 63, and a conduit 64 detachably connected with the conduit 63 through a coupling 65. Introduction of fluid into the piston rod end of the ram cylinder 6| will cause displacement of the ram plungeril to the left and the displacement of fluid from the left end of this ram cylinder through a conduit 66 which is detachably connected with a fluid conducting power take-ofl conduit 61 through a coupling device 68. Fluid discharged through the conduit 66 flows through the conduit 61, a valve passage 69 and a second reversible flow conduit 1|. Inasmuch as at this time the control valve member 26 is moved to the left from the position shown in Fig. 1, and the valve member enlargements 12 and 13 are to the left of their respectively associated ports 49 and 14, the fluid discharged through the conduit 1| will flow through the port 14 and thence into the right end of a channel 15 extending axially of such element. Fluid is discharged from the left end of this channel 15 through the port 46 and the conduit l3 back to the reservoir.

Movement of the motor piston l8 toward the right end of the motor cylinder 45 will continue until it is suflicient to move the control valve .element 26 back to neutral, this movement of the valve element being eflected through the piston rod 22. The walking beam element H at that time pivots about a pivot pin 16 which is held flxed by frictional engagement of the control member l5 with its associated quadrant 10. Con sequently the distance that the motor piston l8 moves in resetting the control valve l4 to neutral for stopping operation of the motor is correlated with the distance of manual setting of the member |5 for initiating the operation. V

Upon movement of the valve element 26 back to neutral, the ports 38 and 46 will be closed again, preventing the escape of fluid from the conduit 35 so that the fluid passing through the restriction 41 can again build up the pressure in the valve chamber 33 causing movement of the piston 4| for unseating the valve ball 42 and recreating the low pressure by-pass condition.

Presuming now that the control member l5 has been moved from position B toward position C, the control valve element 26 will have been shifted to the right uncovering the valve ports 49, 14, 39, and 11. The uncovering of the valve ports 39 and 11 again permits fluid to escape from conduit 35 and the diminution of pressure in the valve chamber 33 so that the by-pass valve ball 42 will again seat and create a high pressure condition. High pressure fluid will then flow through the conduit l2 and through ports 48 and 14 into the reversible flow conduit 1|, the direction of fluid through the conduit 1| having been in the opposite direction in the operation initiated by movement of the control member l5 toward the position A. The fluid continues from the conduit 1| through the valve passage 69 and conduits 61 and 66 into the left end of the ram cylinder 6|. Movement of the ram plunger 2| to the right ensues and displaces fluid from the piston rod end of the cylinder through the conduits 64, 63, 53, check valve 53, and conduit 11 into the piston rod end of the motor cylinder 45. This displaces the motor piston I8 to the left and forces fluid outwardly through the conduit 18 and past the check valve 52 into the conduit 5 I. At this time the check valve 52 is forced open by the pressure of fluid from the conduit II into the chamber I9 above a piston 8I to force this piston downwardly. Conduit 5I communicates with the left end of the valve element passage through the valve port 49 so that the fluid exhausted from the left end of the motor cylinder passes through the passage I5 and thence through port 39 into the conduit I3 for return to the reservoir. In this phase of the operation, the motor piston I8 in moving to the left will cause the walking beam link [1 to swing in the opposite direction about the then fixed pivot I6 for shifting thecontrol valve element 26 toward neutral. The distance that the piston I8 moves is correlated with the distance that the control member I5 had been moved in displacing the valve element 26 from neutral. Again when the valve element 26 is returned to neutral both ports 38 and 39 will be closed to prevent escape of fluid from the conduit 35 so that the fluid introduced through the passage restriction 41 into the valve chamber 33 will be effective for opening the by-pass valve 34 and recreating the low pressure by-pass condition.

Conduit means interconnecting the control valve I4 with the servo-motor I6 includes the two reversible fiow conduits 5| and II. When the valve is operated for causing movement of the motor piston I8 in one direction, fluid is caused to flow from the valve through one of these two conduits and back to the valve through the other of such conduits, and when the valve is adjusted for causing movement of the motor piston I8 in the opposite direction, the direction of flow of fluid through the conduits 5| and II is reversed.

It will also be observed that the hydraulic ram I9 is connected in series with the servo-motor I6. This is more easily comprehended when the conduits TI, 1|, and 63 are regarded as a single conduit leading from the piston rod end of the motor cylinder 45 and when the conduits 'II and 61 are regarded as a single conduit leading from the valve I4. For the motor I6 to be caused to operate, these fabricated conduits 'II'II-63 and II-61 leading respectively from the valve and from the piston rod end of the motor must be connected in series. When a rotatable valve element 9! is in the position shown, the serial connection of these two fabricated conduits 'I'I--'II'--63 and IL-61 are connected in series through the conduits 64 and 66 and the hydraulic ram I9. In other words, the hydraulic ram is interposed in series with the series conduits II'II63 and II-6I.

The linkage interconnecting the piston rod 22, the valve element 26, the rock-shaft 23, and the manually operated control member I5 is so designed in proportion that the fu1l-range movement of the control member I5 will cause full range movement of the piston I8 and will also cause full range rocking movement of the rockshaft arm 25 between its limits A and C For example, when the control member I5 occupies an intermediate position as B, the piston I8 will occupy a correlated mid-position between the two ends of its stroke and the rock-shaft arm 25 will occupy an intermediate position B correlated with position B of the lever I5. By connecting the piston rod end of the ram cylinder 6| with the piston rod end of the motor cylinder 45 by the series conduit 'I1'II'63, and by connecting the opposite .end of the ram cylinder with the control valve through the-other series conduit II-6'! as illustrated in Fig. 1, and by making the displacement capacity of the piston rod end of the ram cylinder equal to that of the piston rod end of the motor cylinder, the motor piston can be caused to occupy positions witihn the range of its stroke correlated with the positions into which the manually controlled member I5 is moved. Assuming that fluid is being introduced into the left end of the ram cylinder 66,

movement 0f the ram plunger 2I to the right will cause displacement of the motor piston I8 to the leftmost end of the motor cylinder 45 only after the ram plunger III has been moved to the piston. rod end of the cylinder 6!. This is because the displacement capacities of the piston rod ends of the two cylinders are the same, wherefore a full stroke of the plunger 2I is necessary to displace enough fluid for satisfying the displacement capacity of the piston rod end of the cylinder 45. Therefore, when the control member I5 is moved into position C and the control valve I4 is thereby set for causing delivery of fluid through the series conduit II6I to the left end of the ram cylinder 6|, the valve will not be reset to neutral until the motor piston I8 has been displaced to the left end of the cylinder 45 to move the rock-shaft arm 25 to position C and this does not occur until the ram plunger 2| has been moved to position C The fact that the displacement capacity of the left end of the rain cylinder BI is greater than the piston rod end thereof and is also greater than either end of the motor cylinder, is immaterial; the pump will continue to deliver fluid from the reservoir into the left end of the ram cylinder until the plunger has been moved to position C coincidentally with whichincident the motor I6 will be operated sufiiciently for returning the control valve to neutral.

When the control member I5 is moved to the limit A of its range of movement, the control valve I4 will be set for causing introduction of fluid into the left end of the motor cylinder 45 and the valve'will not be reset into neutral until the motor piston I8 has moved to the piston rod end of the cylinder, placing the rock-shaft arm 25 in position A Incident to this movement of the motor piston, fluid displaced from the piston rod end of the cylinder 45 will enter the piston rod end of the ram cylinder BI and will thus cause movement of the ram plunger 2I to the left end of the ram cylinder, placing the plunger in position A Despite the ram cylinder having a bore and stroke in excess of that of the motor cylinder, both the extreme and intermediate positions of the ram piston are correlated with the extreme and intermediate positions of the control member I5. This is also true of a ram as that shown in Fig. 2 which has a much shorter stroke than the ram of Fig. 1 but a considerably larger bore. The parts of the ram shown in Fig. 2 respectively corresponding to the parts of the ram in Fig. 1 are designated by the same reference characters with the addition of a prime. However, the tubular piston rod 92' of the ram shown in Fig. 2 is also made of large diameter so the displacement capacity of the piston rod end of the ram 63 interchangeably with the conduit members shown in Fig. l and the system is filled with fluid, manipulation of the manually controlled member I will cause the ram plunger 2| to occupy the position B when the member is in position B and will cause the ram 2| to be in extreme positions A or C when the member 15 is in positions Ann/C respectively. The positions of the plunger 2| and the control member [5 are correlated; throughout their range of movement. The substitution of either ram for fire-other entails no adjustment of the system other than such substitution.

When the valve 9| is rotated 90 from the position shown in Fig. 1, one of the passages 62 or 69 will-connect the conduits 1| and II in direct series while the other of such passages communicates between the fluid conducting powertake-ofi conduits 63 and 61. Conduits H and H are .then, in effect, serially connected sections of a fluid line l|'H' having valve means 9! interposed therebetween, and the fluid conducting power-take-ofl conduits are isolated from such fluid line sections. Operation of the servo-motor i6 is not disturbed by this alternative setting of the valve 9 l In the modification of Fig. 3 the conduit ll connects directly with the check valve 53 and the valve 9! is interposed between fluid line sections M .and H which, when directly connected through one of the valve passages 62 or 69, function similarly to the passage TI in Fig. 1. When the valve 9! is in the position shown in Fig. 3, it

,connects the fluid line sections ll and Tl respectively with the power-take-off conduits 63 and 61 and causes any of the rams as 49 to operate in concert with the motor 45. With this Fig. 3 arrangement the check valves hydraulically lock both the motor and the-remote ram while the valve 9! is in the position shown and while the control valve I4 is in neutral. A more positive hydraulic lock is attainable with the poppet type check valve than if the slidable plunger type control valve were relied on for this function.

Having thus described a limited number of embodiments of the invention with the view of clearly and concisely illustrating the same, I

claim: I

1. In an hydraulic power transmitting system energized from a liquid source having a low pressure inlet and a high pressure outlet, valve means having reversibl flow passages for selective communication with said source and settable in opposite directions from a neutral setting wherein communication of each passage with said source is precluded, said valve means effecting communication of one of the passages with the source outlet and the other passage with the source inlet while set in one direction from neutral and reversing such communications of the passages while set in the opposite direction from neutral, a two-way servo-motor operable by fluid controlled by said valve means and for returning the valve means to neutral, said servo-motor including a fluid-receiving chamber and a work member reversibly movable therein between opposite ends thereof by differential of fluid pressure in the two ends of such chamber, means for selectively setting the valve means away from neutral, means operably connecting the servo-motor work member with the valve means, one of the reversible flow passages being communicative with one end of the servo-motor chamber, conduits leading respectively from the other reversible flow passage and from the other end of the servo-motor chamber, and a plurality of two-way hydraulic rams each having a cylinder, a piston in each cylinder and a piston rod projecting from each piston through an end of the associated cylinder, said rams being interchangeably connectable in series with said conduits o the piston rod end of their cylinder is communicative with the conduit leading from the other end of the servomotor chamber and the opposite end of their cylinder is communicative with the other conduit, such opposite ends of the ram cylinders being of different displacement capacity, and the piston rods of said rams being difierent in diameter for causing the displacement capacit of the piston. rod end of each ram cylinder to equal the displacement capacity of said other end of the servo-motor chamber.

2. In an hydraulic power transmitting system; a source of pressure fluid; control valve means connected with said source; a servo-motor comprising a cylinder, a piston in such cylinder, and a piston rod projecting through a piston-rod end of the cylinder into connection with said valve means to-close the same pursuant to energizetion of such motor; conduit means comprising a conduit connected between the valve and the opposite end of the motor cylinder, and series conduits respectively leading from the piston-rod end of the cylinder and from the valve means; said valve means being openable to accommodate flow of fluid through said conduit means for energizing the motor; and a plurality of rams each comprising a cylinder having a head end and a piston rod end, a piston in such cylinder, and a piston rod extending from the piston through the piston rod end of the cylinder, said rams being interchangeably connectable in series with said series conduits with the piston-rod ends of the ram cylinders connected with the conduit leading from the piston-rod endof the motor cylinder and the opposite ends of the ram cylinders connected with the other series conduit, the displacement capacity of the piston-rod end of each ram cylinder being equal to the displacement capacity of the piston-rod end of the motor cylinder, and the displacement capacity of the opposite ends of the ram cylinders being different.

3. In an hydraulic power transmitting system; a source of pressure fluid; control valve means connected with said source; a servo-motor comprising a cylinder, a piston in such cylinder, and a piston rod projecting through a piston-rod end of the cylinder into connection with said valve means to close the same pursuant to energization of such motor; conduit means comprising a conduit connected between the valve and the opposite end of the motor cylinder, and series conduits respectively leading from the piston-rod end of the cylinder and from the valve means; said valve means being openable to accommodate flow of fluid through said conduit means for energizing the motor; and an hydraulic ram comprising a cylinder having a head end and a piston rod end, a piston in such cylinder, and a piston rod extending from the piston through the piston rod end of the cylinder, said ram being connected in series with said serie conduits in such fashion that the piston-rod end of the ram cylinder is connected with the series conduit leading from the piston-rod end of the motor cylinder and the opposite end of such ram cylinder is connected with the other series conduit, the displacement capacity of the piston-rod end of the ram cylinder being equal to the displacement capacity of the piston-rod end of the motor cylinder, and the 9 stroke of the ram being difierent from that 01' the motor.

4. A hydraulic power transmitting system com- "prising a control valve manipulatable from a neutral setting to accommodate flow of fluid therethrough and resettable to neutral to preclude such flow 0t fluid, a fluid motor operably connected with said valve and energizable by fluid flowable under control of said valve to reset the valve to neutral, fluid lines communicative between the valve and motor for conductin such energizing fluid, check valves respectively in said lines for hydraulically locking the motor while the control valve is in neutral, one of said lines in a portion thereof between its check valve and the motor includin serially connectable sections, a pair of fluid conducting power-take-ofl conduits, and valve means interposed between said 10 serially connectable sections and manipulatable to connect said sections in direct series while isolating them from said conduits and manipulateble to alternatively terminate the direct series connection and connect said sections respectively communicatively with said conduits.

JOSEPH F. ZISKAL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

